The indirect opthalmoscope is an instrument that is worn on an eye doctor's head like a helmet and enables the doctor or other examiner to examine a patient's retina. A light source directs coaxial illumination to facilitate the examiner's view of the retina through the patient's pupil. To use the indirect opthalmoscope, the examiner holds a special focusing lens in one hand near the patient's eye, and uses his other hand to hold the patient's eyelid open. One of the main goals during the retinal examination using the indirect opthalmoscope is to examine the patient's optic nerve and surrounding vessels. To center the optic nerve in the examiner's view, the patient needs to look more in the direction of the examiner's ear rather than at the light source. This is because the optic nerve is not in the visual center of the retina but rather about 15 degrees away from the center.
Thus, if the doctor is examining the patient's right eye, it is necessary for the patient to use his left eye (the eye being examined cannot see much because of the very bright light) to look in the direction of the doctor's right ear, which aligns the optic nerve with the examiner's view. The problem is that the room is usually dark for the examination, and there is a very bright light shining in one eye. This makes it extremely difficult to direct the patient's gaze toward any particular direction, and becomes frustrating for the patient as well as the physician.
There exists an unmet need in the art for a device that can readily direct the patient's gaze in the correct direction during the eye examination so that the doctor can easily see the patient's optic nerve and surrounding retinal vessels.